I know this is an old post, but here goes ..
I would think you would need to address the backspacing issue (spacers or different wheels). I'm thinking of the same setup. My question is ..., has anyone made a 33" tire fit in stock spare location by airing down and wrapping with a ratchet strap (and hitch mod if needed)? Does anyone think it will work?

Sorry I missed this the first time it came through. Busy having fun in the sandbox for uncle sam. Anyway, this is what I am currently running. I have an OME MD lift, and I am running the exact tires the OP was asking about. I won't be able to get any pictures up for a few days though. I am using the JK Rubicon rims with no spacers. I did have to do the pinch weld mod to make them work though. But that is pretty common with tires this size. Also in order to use JK Rubicon rims without spacers you need to grind some material off of the brake caliper mounting brackets. And for a spare I use the standard Rubicon 255/75R17, and I had to grind the crap out of the hitch to fit it. I don't know if a 80 would fit in there without a whole lot of massaging.

Thanks for the input. I'd love to see pics of your setup! Is your 255/75 spare aired up? That's an option I'll have to give some thought to, but I am a little concerned that may be too big a difference in tire size for the QDII if I ever need to use the spare. I am hoping that combining lower pressure and a ratchet strap, I could make the 255/80 fit. but I am also concerned lower pressure in the spare may mess with the TPMS. Anyone have any experience or thoughts on this?

perks of working for a dealer I was able to get a matching 255/75 17 matching BFG MT to match my others worn to 50% +/- ... I had to cut the crap out of my hitch, AND air down the tire... and even then the wheel/tire hangs down and is sollidly wedged where it is.

I'll work on getting some pics soon, I don't check on here very often anymore. According to the Jeep engineers the slightly smaller spare won't adversely effect the QDII. With a 255/75 that is brand new, it really doesn't fit anymore. I don't think you can make a 80 fit with the hitch still in place.